Major nematocyst types used in hydrozoan taxonomy

Nematocysts are highly specialized stinging capsules present in all cnidarians. The types and their forms are often taxonomically very important.

Nematocyst terms and major types of nematocysts used in the Hydrozoa Directory.
Heteronemes have a shaft (thick, basal part of extruded tubule), haplonemes lack a shaft

Nematocysts of Hydra vulgaris, seen with a compound microscope using oil immersion: desmoneme (blue), isorhiza (red), stenotele (green).